1. Field of the Invention
The present invention relates to thromboxane receptor ligands including a carboxylic acid group derivative, which do not cause blood clotting. In particular, the thromboxane receptor ligands are bicyclic carboxylic acid derivatives wherein said bicyclic rings may be hydrocarbyl or oxohydrocarbyl, e.g. 7-[carboxyalkyl or alkenyl]-6-[alkyl or alkenyl]-3-oxo-2,4-dioxobicyclo[3.2.1] octanes and derivatives thereof. In particular, hydroxyl, nitro, amino, amido, azido, oxime, thiol, ether and thiol ether derivatives of said carboxylic acid group are contemplated. In particular, 7-[6-carboxy-2-hexenyl]-6-[3-hydroxy-1-octenyl] 3-oxo-2,4-dioxobicyclo-[3.2.1] octane derivatives are disclosed. These compounds are useful as thromboxane agonists and antagonists. These compounds are also useful as ocular hypotensives.
2. Description of the Related Art
Ocular hypotensive agents are useful in the treatment of a number of various ocular hypertensive conditions, such as post-surgical and post-laser trabeculectomy ocular hypertensive episodes, glaucoma, and as presurgical adjuncts.
Glaucoma is a disease of the eye characterized by increased intraocular pressure. On the basis of its etiology, glaucoma has been classified as primary or secondary. For example, primary glaucoma in adults (congenital glaucoma) may be either open-angle or acute or chronic angle-closure. Secondary glaucoma results from pre-existing ocular diseases such as uveitis, intraocular tumor or an enlarged cataract.
The underlying causes of primary glaucoma are not yet known. The increased intraocular tension is due to the obstruction of aqueous humor outflow. In chronic open-angle glaucoma, the anterior chamber and its anatomic structures appear normal, but drainage of the aqueous humor is impeded. In acute or chronic angle-closure glaucoma, the anterior chamber is shallow, the filtration angle is narrowed, and the iris may obstruct the trabecular meshwork at the entrance of the canal of Schlemm. Dilation of the pupil may push the root of the iris forward against the angle, and may produce pupillary block and thus precipitate an acute attack. Eyes with narrow anterior chamber angles are predisposed to acute angle-closure glaucoma attacks of various degrees of severity.
Secondary glaucoma is caused by any interference with the flow of aqueous humor from the posterior chamber into the anterior chamber and subsequently, into the canal of Schlemm. Inflammatory disease of the anterior segment may prevent aqueous escape by causing complete posterior synechia in iris bombe and may plug the drainage channel with exudates. Other common causes are intraocular tumors, enlarged cataracts, central retinal vein occlusion, trauma to the eye, operative procedures and intraocular hemorrhage.
Considering all types together, glaucoma occurs in about 2% of all persons over the age of 40 and may be asymptotic for years before progressing to rapid loss of vision. In cases where surgery is not indicated, topical .beta.-adrenoreceptor antagonists have traditionally been the drugs of choice for treating glaucoma.
Various U.S. Patents have recently issued which relate to thromboxane ligands and/or treating hemorrhaging. For example, U.S. Pat. Nos. 5,128,322; 5,128,354; 5,149,540; 5,389,630; 5,415,863; 5,436,260; 5,447,712; 5,478,844 and 5,504,090 relate to methods of treating hemorrhaging. U.S. Pat. Nos. 5,248,507; 5,264,220; 5,382,569; 5,409,956; 5,443,848; 5,476,846; 5,480,645; 5,482,960 and 5,504,090 relate to thromboxane ligands. It is thus clear that a great deal of research is currently involved in thromboxane ligands, especially for treating hemorrhaging and related conditions.